ISO 13093:2023 PDF

Overview

ISO 13093:2023 defines a laboratory method for the determination of carbon in titanium and titanium alloys using an infrared absorption method after combustion in a high‑frequency induction furnace under an oxygen atmosphere. The standard covers analysis for carbon contents between 0.003 % and 0.050 % (mass fraction) and specifies required procedures for sample preparation, instrument preparation, blanking, calibration and calculation.

Key topics and technical requirements

• Principle: combust the test portion in an induction furnace in pure oxygen; carbon is converted to CO2 and/or CO and quantified by infrared (IR) absorption.
• Scope of measurement: applicable for carbon from 0.003 % to 0.050 %.
• Reagents & gas: high‑purity oxygen, moisture and CO2 absorbents (e.g., magnesium perchlorate), and accelerators (tungsten, iron or tin) as recommended by the instrument manufacturer.
• Apparatus: high‑frequency induction furnace with IR absorption analyzer, high‑purity ceramic crucibles (pre‑ignited), and gas filters as per manufacturer guidance.
• Sampling & sample prep: use millings/drillings uniform in size (≤5 mm), dry and free from oil/scale; clean with ethanol or acetone.
• Test portion & replication: weigh 200–600 mg (nearest 1 mg); perform determinations at least in duplicate (routine single determinations allowed by agreement).
• Blank tests: perform duplicate blanks using the accelerator only; mean blank must be ≤ 0.001 % and difference between blanks ≤ 5 µg.
• Calibration: use titanium or titanium‑alloy certified reference materials (CRMs/RMs) covering the top, middle and bottom of the method scope; compute an equivalence factor (instrument response → mg C).
• Calculation: subtract blank, apply equivalence factor and sample mass to report carbon as % (mass fraction). Modern analyzers often output %C directly.
• Precision: interlaboratory study (12 labs) yielded concentration‑dependent precision. For example, at 0.003 % C the repeatability r ≈ 0.00074 % and overall reproducibility (smoothed) ≈ 0.0017 %.

Applications and users

This standard is intended for:

• Quality control and materials testing laboratories analyzing titanium and titanium alloys.
• Aerospace, medical‑implant, and specialty metallurgy manufacturers where tight carbon control influences mechanical properties and performance.
• Research labs and certification bodies requiring traceable, validated measurement protocols and CRMs. ISO 13093:2023 supports consistent, comparable carbon measurements for process control, acceptance testing and regulatory compliance.

Related standards

• ISO 5725‑1, ‑2 and ‑3 (precision and accuracy of measurement methods) are referenced for repeatability and reproducibility evaluation.

Keywords: ISO 13093:2023, titanium, titanium alloys, carbon determination, infrared absorption method, induction furnace, carbon content, CRMs, calibration, precision.